Alright i just finished my build and Now i have no 4 wheel drive? it worked before now i get nothing i checked what i thought to be with connections on the front diff they are plugged in and i also looked at the part of the wireing harness that comes down from near the alternator. I see nothing anyone got any ideas. i pop it into 4HI i get nothing no light no 4x4, i pop it into 4LO i can feel the lower gears but still no light and no 4x4. Where are the plug ins for it to kick into 4 wheel?

Sry if you didnt know its a 90 body with a 93 drive terrain

 

If you are talking ADD, its vacuum actuated. The only reason the light comes on, is to let you know the ADD actuator has slid into place thus locking it into 4x4. Are you sure your instrument cluster has the bulb for 4x4?

 

really i didnt know it was vaccume? well darn i guess its one of the lines i blocked off,, DOES anyone have a picture of the 4x4 vacume line so i know which one it is and where it goes? please tell me one of you has one! THANKS

 

So that means no one knows which vacume line works to 4x4 then?

 

I would help ya, but I don;t have ADD on any of my 4Runners.

Why not just yank that ADD junk out, and put in non-ADD jackshaft? Or, just hook it up so its engaged ALL the time, and bolt on manual hubs.

 

i wasnt trying to do all that just yet. i was going to get manual hubs but not for a while. i just got this thing put back together im not trying to do anything else at this moment till i get back to florida but its hard driving around on ice when i have no weight in the rear end and the truck slides all over! so i need my 4x4 to work and its not locking in i just need to know which vacume line plugs in where if anyone can help! thanks...

 

Also i don't know what ADD is and i have no idea if i have it or not i have a 90 truck with 93 drive terrain with auto hubs the 4x4 worked before the swap now nothing!

 

http://www.off-road.com/trucks4x4/ar....jsp?id=399612

The light on your dash is actuated by a switch on your transfer case and one on your ADD, but if the sleeve on your front axle doesn't slide into place, then you won't have 4WD, even with the transfer case engaged.

 

Ok cool now i know what an ADD is! now which vaccume hose makes it work?

 

if you want, ill take a picture for you in the morning...

 

There are two vacuum hoses that come from two VSV's above the front passenger wheel well. Trace those hoses down to the ADD actuator on your front diff (there should be two vacuum ports there.) Plug one hose into each port, and try it. If it works, good... if it doesn't, try swapping the two (you get vacuum from one hose to actuate 4x4, and vacuum from the other to dis-engage it).

By the way... what did you just finish swapping?

Also, you say you have auto hubs... are you sure? or do you just have flanges?

 

HEY SPACE JUNK!! if you can take a picture id REALLY appreciate it!!!

And gallant thanks for the explanation and im pretty sure i got auto hubs you dont have to get out and lock anything in! im not that slow... lol.. And i just did a complete over haul on my truck tranny tcase rear end motor paint interior i build it from scratch! read my sig got a complete build up i just go the motor back in 3 days ago!! And what is "flanges" you got me on that unless your meaning manual locking hubs? i dunno

 

There are three different type of front hub assemblies on Toyota trucks / 4Runners. You can have auto hubs (which I believe only came on vehicles from '84 to '88 or '89... not completely sure). This is what an auto hub looks like:


Then, there are manual hubs. We all know what those are... get out of your vehicle, lock it up, and you're good to go.

Then, with ADD (automatic disconnecting differential), which I believe you have, Toyota uses hub flanges, which essentially act as manual hubs that can't be unlocked. They are essentially a flange plate that the splined end of the CV axle slips into. When your wheel is turning, your CV axle is turning. The hub flange would bolt on with the six small studs shown in the picture below on the hub, and would lock the hub (which turns when the wheel turns) to the splined end of the CV axle.


Finally, here is a picture of the flange installed. There are nuts that go on each of those 6 studs, obviously.